A dual clutch transmission (DCT) combines features of manual and automatic transmissions. For example, a DCT has two input clutches and different oddly-numbered and evenly-numbered gear sets. The input clutches are separately applied to respectively engage the oddly-numbered gear and evenly-numbered gear sets. A controller predicts the next-selected gear using various control inputs such as engine acceleration, vehicle speed, and braking levels, and then commands a staging of the next gear ahead of the impending shift. Relative to an automatic transmission, such staging in advance of the shift can result in faster gear shift speeds, with the DCT design typically providing excellent shift control and power. An automated manual transmission (AMT) is similar in structure to a DCT but has only one input clutch.
In transmission control parlance, the term “creep control” refers to the enforcement of a low level of permitted engine torque at zero throttle. For example, when a driver removes all pressure from a brake pedal while the engine is idling, the vehicle will begin to move or “creep” at a low rate of speed until the driver depresses an accelerator pedal to request additional engine torque. In order to creep in a vehicle having a DCT or an AMT, the input clutch is automatically applied while the engine idles. Regulation of the clutch torque command to the input clutch thus controls the creep torque up to its calibrated maximum allowable level.